from datetime import datetime
from typing import Any, Dict, List, Optional

from pydantic import BaseModel, Field

from letta.schemas.agent import AgentState, CreateAgent
from letta.schemas.block import Block, CreateBlock
from letta.schemas.enums import MessageRole
from letta.schemas.file import FileAgent, FileAgentBase, FileMetadata, FileMetadataBase
from letta.schemas.group import Group, GroupCreate
from letta.schemas.mcp import MCPServer
from letta.schemas.message import Message, MessageCreate
from letta.schemas.source import Source, SourceCreate
from letta.schemas.tool import Tool
from letta.schemas.user import User
from letta.services.message_manager import MessageManager


class ImportResult:
    """Result of an agent file import operation"""

    def __init__(
        self,
        success: bool,
        message: str = "",
        imported_count: int = 0,
        imported_agent_ids: Optional[List[str]] = None,
        errors: Optional[List[str]] = None,
        id_mappings: Optional[Dict[str, str]] = None,
    ):
        self.success = success
        self.message = message
        self.imported_count = imported_count
        self.imported_agent_ids = imported_agent_ids or []
        self.errors = errors or []
        self.id_mappings = id_mappings or {}


class MessageSchema(MessageCreate):
    """Message with human-readable ID for agent file"""

    __id_prefix__ = "message"
    id: str = Field(..., description="Human-readable identifier for this message in the file")

    # Override the role field to accept all message roles, not just user/system/assistant
    role: MessageRole = Field(..., description="The role of the participant.")
    model: Optional[str] = Field(None, description="The model used to make the function call")
    agent_id: Optional[str] = Field(None, description="The unique identifier of the agent")

    @classmethod
    def from_message(cls, message: Message) -> "MessageSchema":
        """Convert Message to MessageSchema"""

        # Create MessageSchema directly without going through MessageCreate
        # to avoid role validation issues
        return cls(
            id=message.id,
            role=message.role,
            content=message.content,
            name=message.name,
            otid=None,  # TODO
            sender_id=None,  # TODO
            batch_item_id=message.batch_item_id,
            group_id=message.group_id,
            model=message.model,
            agent_id=message.agent_id,
        )


class FileAgentSchema(FileAgentBase):
    """File-Agent relationship with human-readable ID for agent file"""

    __id_prefix__ = "file_agent"
    id: str = Field(..., description="Human-readable identifier for this file-agent relationship in the file")

    @classmethod
    def from_file_agent(cls, file_agent: FileAgent) -> "FileAgentSchema":
        """Convert FileAgent to FileAgentSchema"""

        create_file_agent = FileAgentBase(
            agent_id=file_agent.agent_id,
            file_id=file_agent.file_id,
            source_id=file_agent.source_id,
            file_name=file_agent.file_name,
            is_open=file_agent.is_open,
            visible_content=file_agent.visible_content,
            last_accessed_at=file_agent.last_accessed_at,
        )

        # Create FileAgentSchema with the file_agent's ID (will be remapped later)
        return cls(id=file_agent.id, **create_file_agent.model_dump())


class AgentSchema(CreateAgent):
    """Agent with human-readable ID for agent file"""

    __id_prefix__ = "agent"
    id: str = Field(..., description="Human-readable identifier for this agent in the file")
    in_context_message_ids: List[str] = Field(
        default_factory=list, description="List of message IDs that are currently in the agent's context"
    )
    messages: List[MessageSchema] = Field(default_factory=list, description="List of messages in the agent's conversation history")
    files_agents: List[FileAgentSchema] = Field(default_factory=list, description="List of file-agent relationships for this agent")
    group_ids: List[str] = Field(default_factory=list, description="List of groups that the agent manages")

    @classmethod
    async def from_agent_state(
        cls, agent_state: AgentState, message_manager: MessageManager, files_agents: List[FileAgent], actor: User
    ) -> "AgentSchema":
        """Convert AgentState to AgentSchema"""

        create_agent = CreateAgent(
            name=agent_state.name,
            memory_blocks=[],  # TODO: Convert from agent_state.memory if needed
            tools=[],
            tool_ids=[tool.id for tool in agent_state.tools] if agent_state.tools else [],
            source_ids=[],  # [source.id for source in agent_state.sources] if agent_state.sources else [],
            block_ids=[block.id for block in agent_state.memory.blocks],
            tool_rules=agent_state.tool_rules,
            tags=agent_state.tags,
            system=agent_state.system,
            agent_type=agent_state.agent_type,
            llm_config=agent_state.llm_config,
            embedding_config=agent_state.embedding_config,
            initial_message_sequence=None,
            include_base_tools=False,
            include_multi_agent_tools=False,
            include_base_tool_rules=False,
            include_default_source=False,
            description=agent_state.description,
            metadata=agent_state.metadata,
            model=None,
            embedding=None,
            context_window_limit=None,
            embedding_chunk_size=None,
            max_tokens=None,
            max_reasoning_tokens=None,
            enable_reasoner=False,
            from_template=None,  # TODO: Need to get passed in
            template=False,  # TODO: Need to get passed in
            project=None,  # TODO: Need to get passed in
            tool_exec_environment_variables=agent_state.get_agent_env_vars_as_dict(),
            memory_variables=None,  # TODO: Need to get passed in
            project_id=None,  # TODO: Need to get passed in
            template_id=None,  # TODO: Need to get passed in
            base_template_id=None,  # TODO: Need to get passed in
            identity_ids=None,  # TODO: Need to get passed in
            message_buffer_autoclear=agent_state.message_buffer_autoclear,
            enable_sleeptime=False,  # TODO: Need to figure out how to patch this
            response_format=agent_state.response_format,
            timezone=agent_state.timezone or "UTC",
            max_files_open=agent_state.max_files_open,
            per_file_view_window_char_limit=agent_state.per_file_view_window_char_limit,
        )

        messages = await message_manager.list_messages_for_agent_async(
            agent_id=agent_state.id, actor=actor, limit=50
        )  # TODO: Expand to get more messages

        # Convert messages to MessageSchema objects
        message_schemas = [MessageSchema.from_message(msg) for msg in messages]

        # Create AgentSchema with agent state ID (remapped later)
        return cls(
            id=agent_state.id,
            in_context_message_ids=agent_state.message_ids or [],
            messages=message_schemas,  # Messages will be populated separately by the manager
            files_agents=[FileAgentSchema.from_file_agent(f) for f in files_agents],
            group_ids=[agent_state.multi_agent_group.id] if agent_state.multi_agent_group else [],
            **create_agent.model_dump(),
        )


class GroupSchema(GroupCreate):
    """Group with human-readable ID for agent file"""

    __id_prefix__ = "group"
    id: str = Field(..., description="Human-readable identifier for this group in the file")

    @classmethod
    def from_group(cls, group: Group) -> "GroupSchema":
        """Convert Group to GroupSchema"""

        create_group = GroupCreate(
            agent_ids=group.agent_ids,
            description=group.description,
            manager_config=group.manager_config,
            project_id=group.project_id,
            shared_block_ids=group.shared_block_ids,
        )

        # Create GroupSchema with the group's ID (will be remapped later)
        return cls(id=group.id, **create_group.model_dump())


class BlockSchema(CreateBlock):
    """Block with human-readable ID for agent file"""

    __id_prefix__ = "block"
    id: str = Field(..., description="Human-readable identifier for this block in the file")

    @classmethod
    def from_block(cls, block: Block) -> "BlockSchema":
        """Convert Block to BlockSchema"""

        create_block = CreateBlock(
            value=block.value,
            limit=block.limit,
            template_name=block.template_name,
            is_template=block.is_template,
            preserve_on_migration=block.preserve_on_migration,
            label=block.label,
            read_only=block.read_only,
            description=block.description,
            metadata=block.metadata or {},
        )

        # Create BlockSchema with the block's ID (will be remapped later)
        return cls(id=block.id, **create_block.model_dump())


class FileSchema(FileMetadataBase):
    """File with human-readable ID for agent file"""

    __id_prefix__ = "file"
    id: str = Field(..., description="Human-readable identifier for this file in the file")

    @classmethod
    def from_file_metadata(cls, file_metadata: FileMetadata) -> "FileSchema":
        """Convert FileMetadata to FileSchema"""

        create_file = FileMetadataBase(
            source_id=file_metadata.source_id,
            file_name=file_metadata.file_name,
            original_file_name=file_metadata.original_file_name,
            file_path=file_metadata.file_path,
            file_type=file_metadata.file_type,
            file_size=file_metadata.file_size,
            file_creation_date=file_metadata.file_creation_date,
            file_last_modified_date=file_metadata.file_last_modified_date,
            processing_status=file_metadata.processing_status,
            error_message=file_metadata.error_message,
            total_chunks=file_metadata.total_chunks,
            chunks_embedded=file_metadata.chunks_embedded,
            content=file_metadata.content,
        )

        # Create FileSchema with the file's ID (will be remapped later)
        return cls(id=file_metadata.id, **create_file.model_dump())


class SourceSchema(SourceCreate):
    """Source with human-readable ID for agent file"""

    __id_prefix__ = "source"
    id: str = Field(..., description="Human-readable identifier for this source in the file")

    @classmethod
    def from_source(cls, source: Source) -> "SourceSchema":
        """Convert Block to BlockSchema"""

        create_block = SourceCreate(
            name=source.name,
            description=source.description,
            instructions=source.instructions,
            metadata=source.metadata,
            embedding_config=source.embedding_config,
        )

        # Create SourceSchema with the block's ID (will be remapped later)
        return cls(id=source.id, **create_block.model_dump())


# TODO: This one is quite thin, just a wrapper over Tool
class ToolSchema(Tool):
    """Tool with human-readable ID for agent file"""

    __id_prefix__ = "tool"
    id: str = Field(..., description="Human-readable identifier for this tool in the file")

    @classmethod
    def from_tool(cls, tool: Tool) -> "ToolSchema":
        """Convert Tool to ToolSchema"""
        return cls(**tool.model_dump())


class MCPServerSchema(BaseModel):
    """MCP server schema for agent files with remapped ID."""

    __id_prefix__ = "mcp_server"

    id: str = Field(..., description="Human-readable MCP server ID")
    server_type: str
    server_name: str
    server_url: Optional[str] = None
    stdio_config: Optional[Dict[str, Any]] = None
    metadata_: Optional[Dict[str, Any]] = None

    @classmethod
    def from_mcp_server(cls, mcp_server: MCPServer) -> "MCPServerSchema":
        """Convert MCPServer to MCPServerSchema (excluding auth fields)."""
        return cls(
            id=mcp_server.id,  # remapped by serialization manager
            server_type=mcp_server.server_type,
            server_name=mcp_server.server_name,
            server_url=mcp_server.server_url,
            # exclude token, custom_headers, and the env field in stdio_config that may contain authentication credentials
            stdio_config=cls.strip_env_from_stdio_config(mcp_server.stdio_config.model_dump()) if mcp_server.stdio_config else None,
            metadata_=mcp_server.metadata_,
        )

    def strip_env_from_stdio_config(stdio_config: Dict[str, Any]) -> Dict[str, Any]:
        """Strip out the env field from the stdio config."""
        return {k: v for k, v in stdio_config.items() if k != "env"}


class AgentFileSchema(BaseModel):
    """Schema for serialized agent file that can be exported to JSON and imported into agent server."""

    agents: List[AgentSchema] = Field(..., description="List of agents in this agent file")
    groups: List[GroupSchema] = Field(..., description="List of groups in this agent file")
    blocks: List[BlockSchema] = Field(..., description="List of memory blocks in this agent file")
    files: List[FileSchema] = Field(..., description="List of files in this agent file")
    sources: List[SourceSchema] = Field(..., description="List of sources in this agent file")
    tools: List[ToolSchema] = Field(..., description="List of tools in this agent file")
    mcp_servers: List[MCPServerSchema] = Field(..., description="List of MCP servers in this agent file")
    metadata: Dict[str, str] = Field(
        default_factory=dict, description="Metadata for this agent file, including revision_id and other export information."
    )
    created_at: Optional[datetime] = Field(default=None, description="The timestamp when the object was created.")
